Monitoring and analysis solutions for automatically detecting an important phenomenon (hereinafter, event) using data collected through a number of monitoring cameras and various sensors have been developed for the purpose of safety management and security of public spaces and facilities, and are being introduced in many countries in the world. In the field of the safety management and security, there is a requirement for automatically detecting both types of events, one type of event is an event about which the situation may be recognized from a short-time single scene such as intrusion into an off-limits facility and fire, and the other type of event is an event about which the situation may be recognized by observing the progress of circumstances and scale, such as baggage theft and demonstration march.
The event that can be recognized on the basis of a continuous state or movement of a short time, which can be acquired with a sensor including such as a monitoring camera or a microphone, can be detected by a recognition system that operates according to information supplied from each sensor. For example, regarding the detection of fire, a technology is known, that in the case where a smoke detection sensor is already provided in the interior of each building, the sensor device may be set up as a system that recognizes an event indicating the possibility of occurrence of fire, upon sensing smoke. In addition, PTL 1 discloses a technology of distinguishing between carrying away and leaving of a baggage using images of a monitoring camera, and detecting either event.
Further, a technology called complex event processing (hereinafter abbreviated as CEP) is known that includes detecting a specific complex event by combining a plurality of events recognized on the basis of data acquired through one or a plurality of sensors. A system, that employs general CEP technology, such as the one according to NPL 1 stores a rule that prescribes one or more conditions to be satisfied, according to the case where the order of input data is limited, and where the order of input data is not limited. When certain conditions in the stored rule are satisfied, the system executes a state transition, and applies the rule to the input data until reaching a finished state (where all conditions are satisfied). With the CEP designed like above, the result is provides only after all the conditions prescribed in a unit of rules are satisfied.